含砷难浸金精矿柱浸生物氧化回收金

通过室内柱浸试验,对含砷难浸金精矿进行了生物氧化试验。样品经过制粒,用氧化亚铁硫杆菌,在15~28℃条件下分别进行了60 d1、32 d3、02 d的生物浸出,金的氰化浸出率最高达到88.66%,比常规氰化浸出率提高了50个百分点。结果显示,金的浸出率与砷的氧化率呈线性正相关关系;浸出液中Fe3+/Fe2+的氧化还原电位是该体系中的主控电位;细菌浸出液中全铁浓度增量和砷浓度增量呈现出了周期性的变化,这种变化反应了菌种活性的周期性变化,是氧化亚铁硫杆菌不断受到抑制、不断适应的表现。试验证明,用生物堆浸工艺处理含砷难浸金精矿具有一定的可行性,但如何缩短生物氧化时间还需要进一步研究。

Study on Gold Recovery from the Refractory Arsenic Sulphide Concentrate by Column Bio-leaching

Gold recovery from the refractory arsenic sulphide concentrate was studied by column bio-leaching.The agglomerate sample was bio-leached of by thiobacillus ferrooxidans(T.f) at the temperature range of 15～28℃ in period of 60 d,132 d and 302 d respectively,and the highest gold extraction yield was up to 88.66% from 39.97%.The result shows that Au extraction yield was linear with As extraction yield;that the oxidation-reduce potential of Fe~(3+)/Fe~(2+)was primary potential in leaching solution and that the T.f activity varied periodically due to inhabiting and accommodating.From the experiments,we realized the heap bio-leaching technology may be applied on refractory gold concentrate,and further study should be made in relation to shorten the bio-leaching time.